Abstract

Subjects drawn from a variety of populations were required to build simple models of geometric figures, pictures of which they were shown. The time taken 10 build each model was measured and its correctness assessed. It was found that it was probably erroneous to disregard time on the grounds that in certain cultures time has a relatively low social value when assessing subjects' performance. The best index of performance, the results tentatively suggest, is probably the ratio of the total time used by a subject to the number of correct responses. This offers a superior measure of the perceptual difficulties than either of the primary measures taken on its own.